N: 80 S: -70 E: 180 W: -180
Description
A regional Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in real-time from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-19 platform (launched 6 Feb 2009) produced and used operationally in oceanographic analyses and forecasts by the US Naval Oceanographic Office (NAVO). The AVHRR is a space-borne scanning sensor on the National Oceanic and Atmospheric Administration (NOAA) family of Polar Orbiting Environmental Satellites (POES) having a operational legacy that traces back to the Television Infrared Observation Satellite-N (TIROS-N) launched in 1978. AVHRR instruments measure the radiance of the Earth in 5 (or 6) relatively wide spectral bands. The first two are centered around the red (0.6 micrometer) and near-infrared (0.9 micrometer) regions, the third one is located around 3.5 micrometer, and the last two sample the emitted thermal radiation, around 11 and 12 micrometers, respectively. The legacy 5 band instrument is known as AVHRR/2 while the more recent version, the AVHRR/3 (first carried on the NOAA-15 platform), acquires data in a 6th channel located at 1.6 micrometer. Typically the 11 and 12 micron channels are used to derive SST sometimes in combination with the 3.5 micron channel. The NOAA platforms are sun synchronous generally viewing the same earth location twice a day (latitude dependent) due to the relatively large AVHRR swath of approximately 2400 km. The highest ground resolution that can be obtained from the current AVHRR instruments is 1.1 km at nadir. AVHRR data are acquired in three formats: High Resolution Picture Transmission (HRPT), Local Area Coverage (LAC), and Global Area Coverage (GAC). HRPT data are full resolution image data transmitted to a ground stations as they are collected. LAC are also full resolution data, but the acquisition is prescheduled and recorded with an on-board tape recorder for subsequent transmission during a station overpass. GAC data provide daily subsampled global coverage recorded on tape recorders and then transmitted to a ground station. This particular dataset is derived from LAC data. Further binning and averaging of the 1.1 km LAC pixels results in a final dataset resolution of 2.2 km. The coverage of the LAC data can vary but generally contains scenes over the oceans adjacent to Australia and the North Indian Ocean.
Product Summary
Citation
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Variables
The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.
For questions on a specific variable, please use the Earthdata Forum.
| Name Sort descending | Description | Units | Data Type | Fill Value | Valid Range | Scale Factor | Offset |
|---|---|---|---|---|---|---|---|
| adi_dtime_from_sst | time difference with NAAPS forecast | hour | byte | -128 | -127 to 127 | 0.1 | N/A |
| aerosol_dynamic_indicator | Aerosol optical depth provided from the Navy Aerosol Analysis and Prediction System (NAAPS) global aerosol prediction system. | count | byte | -128 | -127 to 127 | 0.006 | 0.75 |
| brightness_temperature_4um | non L2P core field; brightness temperature for 3.7 um channel AVHRR channel 3 | kelvin | short | -32768 | -5000 to 5000 | 0.01 | 273.15 |
| brightness_temperature_11um | non L2P core field; brightness temperature for 10.8 um channel AVHRR channel 4 | kelvin | short | -32768 | -5000 to 5000 | 0.01 | 273.15 |
| brightness_temperature_12um | non L2P core field; brightness temperature for 12.0 um channel AVHRR channel 5 | kelvin | short | -32768 | -5000 to 5000 | 0.01 | 273.15 |
| dt_analysis | Deviation from NAVOCEANO 10-km SST gridded field (K10) | kelvin | byte | -128 | -127 to 127 | 0.1 | N/A |
| l2p_flags | no retrieval made on land or ice. SST over lakes and river are not identified | N/A | short | 2048 | 0 to 2047 | 1 | N/A |
| lat | Latitude of retrievals | degrees_north | float | N/A | -90 to 90 | 1 | N/A |
| lon | Longitude of retrievals | degrees_east | float | N/A | -180 to 180 | 1 | N/A |
| quality_level | Based on NAVOCEANO reliability estimates | N/A | byte | 0 | 0 to 5 | 1 | N/A |
| satellite_zenith_angle | satellite zenith angle | angular degree | byte | -128 | -127 to 127 | 1 | N/A |
| sea_surface_temperature | SST obtained by regression from buoy measurements at 1 m depth | kelvin | short | -32768 | -5000 to 5000 | 0.01 | 273.15 |
| sses_bias | Updated daily based on previous month match-ups | kelvin | byte | -128 | -127 to 127 | 0.01 | N/A |
| sses_standard_deviation | Updated daily based on previous month match-ups | kelvin | byte | -128 | -127 to 127 | 0.01 | 1 |
| sst_dtime | none | second | short | -32768 | -32767 to -32767 | 0.25 | N/A |
| time | seconds since 1981-01-01 00:00:00 | seconds since 1981-01-01 00:00:00 | int | N/A | N/A | 1 | N/A |
| wind_speed | wind speed is not available | m s-1 | byte | -128 | -127 to 127 | 0.15 | N/A |